1. Field of the Invention
The present invention relates to a machine tool, and more particularly, to a machine tool with a cover structure adapted for the discharge of chips.
2. Description of the Related Art
In a machine tool, chips produced during machining adhere to or are deposited inside a metal plate cover that covers a machining area or on the surface of another cover component. In order to continue normal use of the machine tool, the chips must be removed. In doing this, the chips are washed away by a cutting fluid and collected in a cutting fluid supply device.
As described in Japanese Patent Applications Laid-Open Nos. 2007-61998 and 2006-7391, therefore, a metal plate cover that receives chips is generally shaped so that a portion thereof that contacts a casting component located in the center of a machine is formed at the lowest level and the cover is gradually elevated from the lowest portion toward its outer peripheral portion.
In the technique disclosed in Japanese Patent Application Laid-Open No. 2007-61998 described above, the adopted shape of the metal plate cover induces the chips and cutting fluid to collect in an area near a drive unit (not shown) of the machine. If the chips are deposited on the bottom surface of the cover, they adhere to a linear-motion guide or feed screw of a drive system, possibly causing trouble. Since the cutting fluid probably splashes, moreover, it inevitably carries away a lubricant applied to the drive system and may cause a malfunction of the machine. This problem can be partially solved by the technique described in Japanese Patent Application Laid-Open No. 2006-7391, but not fully.